SummaryWe examined whether the extract from Hatakeshimeji ( Lyophyllum decastes , LD) mushrooms suppresses the development of atopic dermatitis (AD)-like skin lesions induced by repeated application of picryl chloride (PiCl) in NC/Nga mice. Oral administration of LD extract to NC/Nga mice inhibited the development of AD-like skin lesions based on lower total skin severity scores and serum immunoglobulin E (IgE) levels. Splenic lymphocytes were stimulated with the T cell mitogen concanavalin A, and secretion of a Th1 cytokine (IFN-␥ ) and a Th2 cytokine (IL-4) was determined by ELISA. IFN-␥ production was not inhibited by treatment with LD extract. On the other hand, IL-4 production was significantly decreased by treatment with LD extract. These results suggest that LD extract exerts anti-allergic actions by suppressing the serum IgE and Th2-type immune responses.

We established a method for producing two types of xylooligosaccharides by treating kraft pulp derived from hardwood such as eucalyptus with xylanase, analyzed the structure by MALDI-TOF-MS/MS, and conducted an in vitro study on utilization by intestinal bacteria. One type was a neutral xylooligosaccharide (XOS), a xylooligomer in the D.P. range of dimer to approximately 17-mer, containing approximately 12% xylobiose. The other was an acidic xylooligosaccharide (U-XOS), a xylooligomer in the D.P. range of dimer to approximately 17-mer, with a major side chain of 4-O-methyl-glucuronic acid and other side chains of glucuronic acid and 2-O-galactopyranosyl-4-O-methyl-glucurono acid. The in vitro utilization study with intestinal bacteria showed that XOS was specifically utilized by Bifidobacterium, whereas U-XOS was utilized by only a few types of bacteria. In a fecal batch culture, both XOS and U-XOS selectively increased the population of Bifidobacterium. The present study proposes a new method for industrial production of XOS and U-XOS, and indicates the utility and functionality.

Summary Iron deficiency anemia (IDA) is one of the most serious forms of malnutrition. This experiment was conducted to investigate whether acidic xylooligosaccharide (U-XOS), expected to have a high iron bioavailability, was useful in the prevention of iron deficiency. Experiment 1: Nineteen female Sprague-Dawley rats (20 wk old) were fed three different diets for 28 d; a U-XOS-supplemented low-iron diet (LI-X, n ϭ 7), a low-iron diet (LI, n ϭ 6), and a control diet (C, n ϭ 6). On day 28, the LI-X and LI groups showed iron deficiency without anemia. A significant difference in the total and unsaturated iron binding capacity, and serum transferrin saturation level was shown in the LI-X and LI groups, compared with the C group. However, the decrease of hepatic iron content of the LI-X group was suppressed compared with the LI group. Experiment 2: Eleven male Sprague-Dawley rats (7 wk old) were fed a U-XOS-supplemented diet (X, n ϭ 5) or a control diet (C, n ϭ 6) for 7 d. No significant difference in body weight gain or food intake was demonstrated between the two groups; the apparent iron absorption rate of the X group increased clearly compared with that of the C group. These results suggested that a U-XOS diet could preserve storage of hepatic iron in adult female rats fed a low-iron diet and could prevent IDA by promotion of dietary iron absorption, inhibition of iron excretion, and/or improvement of iron bioavailability.

SummaryWe examined whether two types of xylooligosaccharides (neutral or acidic xylooligosaccharides) derived from hardwood kraft pulp ameliorate the development of atopic dermatitis (AD)-like skin lesions induced by repeated application of picryl chloride (PiCl) in NC/Nga mice. Oral administration of acidic xylooligosaccharides at a daily dose of 100 mg/kg significantly prevented the development of AD-like skin lesions. Serum histamine level was significantly suppressed, but serum total IgE level was not significantly suppressed. Moreover, the secretion of inflammatory cytokine IL-12 from splenic lymphocytes was significantly suppressed. On the other hand, neutral xylooligosaccharides showed no significant preventive effect on the development of AD-like symptoms. These results suggest that oral administration of acidic xylooligosaccharides may be effective in preventing the development of AD-like skin disease and one of the mechanisms is the suppressive effect on IL-12.